/* ── Reset & Base ─────────────────────────────────────────────────────────── */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #08080e;
  --bg-card: #0f0f18;
  --bg-card-hover: #15151f;
  --bg-nav: #0c0c14;
  --border: rgba(255, 255, 255, 0.06);
  --border-hover: rgba(255, 255, 255, 0.12);
  --text-primary: #f0f0f8;
  --text-secondary: #a8b2c6;
  --text-muted: #6e7a90;
  --font-body: 'Inter', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --radius-pill: 999px;
  --accent: #4f8ef7;
  --journal-color: #4f8ef7;  /* overridden per-journal by JS */
  --transition: 0.18s ease;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--journal-color);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* ── Header ────────────────────────────────────────────────────────────────── */

.site-header {
  background: linear-gradient(180deg, rgba(8,8,14,1) 0%, rgba(8,8,14,0.9) 100%);
  border-bottom: 1px solid var(--border);
  padding: 2.5rem 1.5rem 2rem;
  position: relative;
  overflow: hidden;
}

.site-header::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 80% 60% at 50% -20%, rgba(79, 142, 247, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

.header-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.header-eyebrow {
  display: block;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--journal-color);
  margin-bottom: 0.4rem;
  opacity: 0.9;
}

.header-title {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 900;
  letter-spacing: -0.03em;
  line-height: 1.05;
  background: linear-gradient(135deg, #f0f0f8 30%, #8892a4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.header-sub {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  font-weight: 400;
}

.update-badge {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 0.4rem 0.9rem;
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--text-secondary);
  white-space: nowrap;
}

.update-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: #3ecf8e;
  box-shadow: 0 0 6px #3ecf8e;
  flex-shrink: 0;
}

/* ── Nav Wrapper (sticky two-level nav) ───────────────────────────────────── */

.nav-wrapper {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg-nav);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 1280px;
  margin: 0 auto;
}

/* ── Publisher Nav ────────────────────────────────────────────────────────── */

.publisher-nav {
  display: flex;
  gap: 0.35rem;
  padding: 0.7rem 1.5rem 0;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  border-bottom: 1px solid var(--border);
}

.publisher-nav::-webkit-scrollbar { display: none; }

.publisher-btn {
  flex-shrink: 0;
  background: transparent;
  border: none;
  border-bottom: 2px solid transparent;
  padding: 0.45rem 0.9rem 0.6rem;
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition);
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  margin-bottom: -1px;
}

.publisher-btn:hover {
  color: var(--text-secondary);
}

.publisher-btn.active {
  color: var(--pub-color);
  border-bottom-color: var(--pub-color);
}

.pub-count {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 500;
  background: rgba(255,255,255,0.07);
  border-radius: var(--radius-pill);
  padding: 0.1rem 0.4rem;
  color: var(--text-muted);
}

.publisher-btn.active .pub-count {
  background: color-mix(in srgb, var(--pub-color) 18%, transparent);
  color: var(--pub-color);
}

/* ── Journal Nav Tabs ─────────────────────────────────────────────────────── */

.journal-nav {
  display: flex;
  gap: 0.4rem;
  padding: 0.6rem 1.5rem;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

.journal-nav::-webkit-scrollbar { display: none; }

.tab-btn {
  flex-shrink: 0;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 0.4rem 1rem;
  font-family: var(--font-body);
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition), background var(--transition), box-shadow var(--transition);
  letter-spacing: 0.01em;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.tab-btn:hover {
  color: var(--text-primary);
  border-color: var(--border-hover);
  background: rgba(255,255,255,0.04);
}

.tab-btn.active {
  color: #fff;
  border-color: var(--journal-color);
  background: color-mix(in srgb, var(--journal-color) 15%, transparent);
  box-shadow: 0 0 12px color-mix(in srgb, var(--journal-color) 25%, transparent);
}

.tab-short {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
}

.tab-name {
  display: none;
}

@media (min-width: 640px) {
  .tab-name { display: inline; }
  .tab-short { display: none; }
}

/* ── Main Content ─────────────────────────────────────────────────────────── */

.main-content {
  flex: 1;
  max-width: 1280px;
  width: 100%;
  margin: 0 auto;
  padding: 2rem 1.5rem;
}

/* ── Loading / Error States ───────────────────────────────────────────────── */

.loading-state,
.error-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 40vh;
  gap: 1rem;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

.spinner {
  width: 36px;
  height: 36px;
  border: 2px solid var(--border);
  border-top-color: var(--journal-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.error-state {
  color: #f87171;
}

/* ── Journal View ─────────────────────────────────────────────────────────── */

.journal-view {
  animation: fadeIn 0.25s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

.journal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
  gap: 1rem;
  flex-wrap: wrap;
}

.journal-header-left {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.journal-publisher-badge {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-pill);
  border: 1px solid;
  white-space: nowrap;
}

.journal-name {
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.journal-header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.journal-link {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--journal-color);
  opacity: 0.8;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  transition: opacity var(--transition);
}

.journal-link:hover {
  opacity: 1;
  text-decoration: none;
}

/* ── Sections Grid ────────────────────────────────────────────────────────── */

.sections-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  align-items: start;
}

@media (max-width: 600px) {
  .sections-grid {
    grid-template-columns: 1fr;
  }
}

/* ── Section Column ───────────────────────────────────────────────────────── */

.section-col {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.section-heading {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.1rem;
}

.section-label {
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--journal-color);
}

/* ── Cite Toggle ──────────────────────────────────────────────────────────── */

.cite-toggle {
  display: flex;
  gap: 2px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 2px;
}

.cite-toggle-btn {
  background: transparent;
  border: none;
  border-radius: var(--radius-pill);
  padding: 0.25rem 0.7rem;
  font-family: var(--font-body);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--text-muted);
  cursor: pointer;
  transition: background var(--transition), color var(--transition), box-shadow var(--transition);
  white-space: nowrap;
}

.cite-toggle-btn:hover {
  color: var(--text-secondary);
}

.cite-toggle-btn.active {
  background: color-mix(in srgb, var(--toggle-color) 18%, transparent);
  color: var(--toggle-color);
  box-shadow: 0 0 8px color-mix(in srgb, var(--toggle-color) 20%, transparent);
}

/* ── ──────────────────────────────────────────────────────────────────────── */

.section-info-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-muted);
  font-size: 0.75rem;
  line-height: 1;
  padding: 2px;
  border-radius: 50%;
  transition: color var(--transition);
  position: relative;
}

.section-info-btn:hover {
  color: var(--text-secondary);
}

.section-tooltip {
  position: absolute;
  top: calc(100% + 6px);
  left: 50%;
  transform: translateX(-50%);
  background: #1a1a26;
  border: 1px solid var(--border-hover);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.75rem;
  font-size: 0.72rem;
  color: var(--text-secondary);
  width: 220px;
  z-index: 20;
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.15s;
  line-height: 1.5;
  text-align: left;
}

.section-info-btn:hover .section-tooltip,
.section-info-btn:focus .section-tooltip {
  opacity: 1;
}

/* ── Paper Card ───────────────────────────────────────────────────────────── */

.paper-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.1rem 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition), transform var(--transition);
  position: relative;
  overflow: hidden;
}

.paper-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: var(--journal-color);
  opacity: 0.7;
  border-radius: 3px 0 0 3px;
}

.paper-card:hover {
  background: var(--bg-card-hover);
  border-color: color-mix(in srgb, var(--journal-color) 25%, var(--border));
  box-shadow: 0 0 24px color-mix(in srgb, var(--journal-color) 10%, transparent),
              0 2px 12px rgba(0,0,0,0.4);
  transform: translateY(-1px);
}

.paper-rank {
  position: absolute;
  top: 0.7rem;
  right: 0.9rem;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-muted);
  font-weight: 500;
}

.paper-topics {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  min-height: 0;
}

.topic-chip {
  display: inline-block;
  font-size: 0.62rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-pill);
  opacity: 0.9;
  white-space: nowrap;
  text-transform: uppercase;
  cursor: pointer;
  transition: opacity var(--transition), filter var(--transition);
}

.topic-chip:hover {
  opacity: 1;
  filter: brightness(1.2);
}

.paper-title {
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--text-primary);
  padding-right: 1.2rem; /* room for rank badge */
}

.paper-title a {
  color: inherit;
  transition: color var(--transition);
}

.paper-title a:hover {
  color: var(--journal-color);
  text-decoration: none;
}

.paper-authors {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.4;
  font-weight: 400;
}

.paper-authors a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition);
}

.paper-authors a:hover {
  color: var(--journal-color);
  text-decoration: underline;
}

.paper-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-top: auto;
  padding-top: 0.4rem;
  border-top: 1px solid rgba(255,255,255,0.04);
  flex-wrap: wrap;
}

.paper-meta {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.meta-badge {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.meta-badge .badge-icon {
  font-size: 0.65rem;
}

.meta-badge-journal {
  font-family: var(--font-body);
  font-style: italic;
  margin-left: auto;
  color: var(--text-secondary);
  opacity: 0.8;
}

/* ── Paper Slot (show-more wrapper) ─────────────────────────────────────── */

.paper-slot[hidden] { display: none; }

/* ── Show More ────────────────────────────────────────────────────────────── */

.show-more-btn {
  margin-top: 0.5rem;
  width: 100%;
  padding: 0.5rem;
  background: none;
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  color: var(--text-secondary);
  font-size: 0.75rem;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}

.show-more-btn:hover {
  border-color: var(--journal-color, var(--text-secondary));
  color: var(--text-primary);
}

/* ── Empty State ──────────────────────────────────────────────────────────── */

.empty-card {
  background: var(--bg-card);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* ── Header Search ────────────────────────────────────────────────────────── */

.header-search {
  flex-grow: 1;
  max-width: 380px;
  min-width: 140px;
}

#search-input {
  width: 100%;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 0.45rem 1rem;
  font-family: var(--font-body);
  font-size: 0.82rem;
  color: var(--text-primary);
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
}

#search-input::placeholder {
  color: var(--text-muted);
}

#search-input:focus {
  border-color: color-mix(in srgb, var(--journal-color) 50%, var(--border));
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--journal-color) 12%, transparent);
}

/* ── Search Results ───────────────────────────────────────────────────────── */

.search-results-header {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.search-results-count {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.search-results-count em {
  color: var(--text-secondary);
  font-style: normal;
  font-weight: 600;
}

.search-filter-tabs {
  display: inline-flex;
  gap: 2px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 2px;
}

.search-filter-btn {
  background: transparent;
  border: none;
  border-radius: var(--radius-pill);
  padding: 0.25rem 0.7rem;
  font-family: var(--font-body);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.35rem;
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
}

.search-filter-btn:hover {
  color: var(--text-secondary);
}

.search-filter-btn.active {
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  color: var(--accent);
}

.search-filter-count {
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 500;
  background: rgba(255,255,255,0.07);
  border-radius: var(--radius-pill);
  padding: 0.05rem 0.35rem;
  color: var(--text-muted);
}

.search-filter-btn.active .search-filter-count {
  background: color-mix(in srgb, var(--accent) 20%, transparent);
  color: var(--accent);
}

.search-cards {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 680px;
}

.search-result-item {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.search-journal-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--journal-color);
  padding-left: 0.2rem;
}

/* ── Overview View ───────────────────────────────────────────────────────── */

.overview-view {
  animation: fadeIn 0.25s ease;
}

.overview-header {
  margin-bottom: 1.5rem;
}

.overview-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 0 0 0.25rem;
}

.overview-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin: 0;
}

.trends-anchor-btn {
  background: none;
  border: none;
  padding: 0;
  font-family: inherit;
  font-size: inherit;
  font-weight: 500;
  color: var(--accent);
  cursor: pointer;
  transition: color var(--transition);
}

.trends-anchor-btn:hover {
  color: var(--text-primary);
  text-decoration: underline;
}

/* ── Trends View ──────────────────────────────────────────────────────────── */

.trends-view {
  animation: fadeIn 0.25s ease;
  max-width: 720px;
}

.trends-section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

.trends-header {
  margin-bottom: 2rem;
}

.trends-title {
  font-size: clamp(1.1rem, 2.5vw, 1.5rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 0.35rem;
}

.trends-sub {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0.75rem;
}

.trends-toggle {
  display: inline-flex;
  gap: 2px;
  background: rgba(255,255,255,0.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 2px;
}

.trends-toggle-btn {
  background: transparent;
  border: none;
  border-radius: var(--radius-pill);
  padding: 0.25rem 0.7rem;
  font-family: var(--font-body);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--text-muted);
  cursor: pointer;
  transition: background var(--transition), color var(--transition), box-shadow var(--transition);
  white-space: nowrap;
}

.trends-toggle-btn:hover {
  color: var(--text-secondary);
}

.trends-toggle-btn.active {
  background: color-mix(in srgb, var(--accent) 18%, transparent);
  color: var(--accent);
  box-shadow: 0 0 8px color-mix(in srgb, var(--accent) 20%, transparent);
}

.chart-bars {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  max-width: 720px;
}

.chart-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.chart-label {
  -webkit-appearance: none;
  appearance: none;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--text-secondary);
  width: 130px;
  flex-shrink: 0;
  text-align: right;
  text-transform: lowercase;
  background: transparent;
  border: none;
  padding: 0;
  margin: 0;
  cursor: pointer;
  transition: color var(--transition);
}

.chart-label:hover {
  color: var(--accent);
}

.chart-bar-wrap {
  flex: 1;
  background: rgba(255,255,255,0.04);
  border-radius: var(--radius-pill);
  height: 22px;
  overflow: hidden;
}

.chart-bar {
  height: 100%;
  background: color-mix(in srgb, var(--journal-color) 35%, transparent);
  border-radius: var(--radius-pill);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 0.5rem;
  min-width: 2rem;
  transition: width 0.4s ease;
}

.chart-count {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  color: var(--text-secondary);
  white-space: nowrap;
}

/* ── Topic Cluster Cards ─────────────────────────────────────────────────── */

.cluster-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 0.75rem;
}

@media (max-width: 600px) {
  .cluster-grid {
    grid-template-columns: 1fr;
  }
}

.cluster-card {
  -webkit-appearance: none;
  appearance: none;
  background: var(--bg-card);
  color: inherit;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  cursor: pointer;
  transition: border-color var(--transition), background var(--transition);
  text-align: left;
  font-family: var(--font-body);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.cluster-card:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
}

.cluster-name {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--text-primary);
  text-transform: capitalize;
}

.cluster-count {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: var(--text-muted);
}

.cluster-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: 0.2rem;
}

.cluster-kw {
  font-size: 0.65rem;
  font-family: var(--font-mono);
  color: var(--accent);
  background: color-mix(in srgb, var(--accent) 10%, transparent);
  border-radius: var(--radius-pill);
  padding: 0.15rem 0.5rem;
}

/* ── Paper Details Button ─────────────────────────────────────────────────── */

.paper-details-btn {
  background: transparent;
  border: 1px solid var(--border);
  border-radius: var(--radius-pill);
  padding: 0.2rem 0.65rem;
  font-family: var(--font-body);
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  white-space: nowrap;
  transition: color var(--transition), border-color var(--transition), background var(--transition);
  margin-left: auto;
  flex-shrink: 0;
}

.paper-details-btn:hover {
  color: var(--journal-color);
  border-color: var(--journal-color);
  background: color-mix(in srgb, var(--journal-color) 8%, transparent);
}

/* ── Paper Modal ──────────────────────────────────────────────────────────── */

.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 100;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.modal-overlay.open {
  display: flex;
}

.modal-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-hover);
  border-radius: var(--radius);
  padding: 2rem;
  max-width: 640px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  animation: fadeIn 0.2s ease;
}

.modal-close-btn {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background: none;
  border: none;
  color: var(--text-muted);
  font-size: 0.9rem;
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-sm);
  transition: color var(--transition), background var(--transition);
  line-height: 1;
}

.modal-close-btn:hover {
  color: var(--text-primary);
  background: rgba(255,255,255,0.06);
}

.modal-title {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text-primary);
  padding-right: 2rem;
}

.modal-authors {
  font-size: 0.82rem;
  color: var(--text-secondary);
}

.modal-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.modal-abstract {
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--text-secondary);
}

.modal-abstract-empty {
  color: var(--text-muted);
  font-style: italic;
}

.modal-link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  align-self: flex-start;
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  border-radius: var(--radius-pill);
  padding: 0.45rem 1.1rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  transition: background var(--transition), border-color var(--transition);
  margin-top: 0.25rem;
}

.modal-link-btn:hover {
  background: color-mix(in srgb, var(--accent) 25%, transparent);
  border-color: color-mix(in srgb, var(--accent) 55%, transparent);
  text-decoration: none;
}

/* ── Footer ───────────────────────────────────────────────────────────────── */

.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--border);
  padding: 1.25rem 1.5rem;
  background: var(--bg-nav);
}

.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer-text {
  font-size: 0.75rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-text a {
  color: var(--text-secondary);
  transition: color var(--transition);
}

.footer-text a:hover {
  color: var(--text-primary);
  text-decoration: none;
}

.footer-source {
  font-size: 0.73rem;
}

.footer-source a {
  color: var(--text-muted);
  transition: color var(--transition);
}

.footer-source a:hover {
  color: var(--text-secondary);
  text-decoration: none;
}

/* ── Scrollbar (Webkit) ───────────────────────────────────────────────────── */

::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.1);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(255,255,255,0.18);
}

/* ── Accessibility ────────────────────────────────────────────────────────── */

:focus-visible {
  outline: 2px solid var(--journal-color);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ── Journal Trends Section ──────────────────────────────────────────────── */

.journal-trends-section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}

/* ── Trends controls row ─────────────────────────────────────────────────── */

.trends-header-controls {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.5rem;
  margin-top: 0.75rem;
}

.trends-controls-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}

.trends-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin: 0.75rem 0 1rem;
}

.section-filter {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.section-filter-btn {
  padding: 0.2rem 0.6rem;
  font-size: 0.72rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.section-filter-btn.active {
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  color: var(--accent);
}

.section-filter-btn:hover:not(.active) {
  border-color: var(--text-secondary);
  color: var(--text-primary);
}

.year-range-filter {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.year-range-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.year-range-sep {
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.year-range-select {
  font-size: 0.75rem;
  padding: 0.2rem 0.4rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
  color: var(--text-primary);
  cursor: pointer;
}

/* ── By-Year Chart ───────────────────────────────────────────────────────── */

.byyear-chart {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.byyear-group {
  display: grid;
  grid-template-columns: 3rem 1fr;
  gap: 0.5rem;
  align-items: start;
}

.byyear-year {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding-top: 0.15rem;
  text-align: right;
}

.byyear-bars {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.byyear-row {
  display: grid;
  grid-template-columns: 130px 1fr;
  align-items: center;
  gap: 0.5rem;
}

.byyear-topic {
  font-size: 0.72rem;
  color: var(--text-secondary);
  text-align: right;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.byyear-bar-wrap {
  background: var(--bg-card);
  border-radius: 2px;
  height: 1.1rem;
  position: relative;
}

.byyear-bar {
  height: 100%;
  border-radius: 2px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 0.3rem;
  min-width: 1.5rem;
  transition: width 0.2s ease;
}

.byyear-count {
  font-size: 0.65rem;
  font-weight: 600;
  white-space: nowrap;
}

/* ── Alluvial Chart ──────────────────────────────────────────────────────── */

.alluvial-wrapper {
  width: 100%;
  overflow-x: auto;
}

.alluvial-wrapper svg {
  min-width: 400px;
}

/* ── Heatmap ─────────────────────────────────────────────────────────────── */

.heatmap-scroll {
  overflow-x: auto;
  width: 100%;
}

.heatmap-grid {
  display: grid;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  min-width: 600px;
}

.hm-cell {
  padding: 0.35rem 0.4rem;
  font-size: 0.7rem;
  border-right: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
}

.hm-cell:last-child,
.hm-cell:nth-child(var(--hm-cols)) {
  border-right: none;
}

.hm-corner {
  background: var(--bg-card);
}

.hm-header {
  background: var(--bg-card);
  writing-mode: vertical-lr;
  transform: rotate(180deg);
  text-align: center;
  font-weight: 600;
  color: var(--text-secondary);
  min-height: 60px;
  padding: 0.5rem 0.25rem;
}

.hm-abbrev {
  font-size: 0.65rem;
  letter-spacing: 0.03em;
}

.hm-topic {
  justify-content: flex-end;
  text-align: right;
  background: var(--bg-card);
  color: var(--text-secondary);
  font-size: 0.7rem;
  padding-right: 0.5rem;
  border-right: 1px solid var(--border);
}

.hm-value {
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: background 0.15s;
}

.hm-count {
  opacity: 0.9;
}